You Are Here: Management Updates 2007 Archive May 31, 2007

Date: May 31, 2007
Category: Insects
Subject: Annual Bluegrass (Hyperodes) Weevil, White Grubs, Billbugs

Annual bluegrass weevils
The word we are getting is that annual bluegrass weevils (a.k.a. Hyperodes weevils) are in the largest larval stages in southeastern Pennsylvania. We can expect them to be in the large feeding stages in southern New York and southeastern Connecticut next week, if not sooner, so the telltale signs of damage should start showing up soon. Those of you on golf courses in central New England can expect to see the "action" starting late next week or early the following week (i.e., between 5 and 15 June).

If you are seeing evidence of damage in the heavily infested areas, you can get some relief by using a fast-acting product like trichlorfon (Dylox™). Studies in previous years also indicate that spinosad (Conserve™) can provide some reduction in populations if applied when the larvae are already present but still quite small.

White grubs
White grubs have been active for several weeks in most areas. It is probably too late to try and control the grubs that are present now, but turf managers should make a note of where the grubs are active now, and be prepared to protect those areas a little later in the growing season. There are three active ingredients that can be used preventively. In each case, these products are most effective against white grubs if applied when the adult beetles are laying eggs or just after the eggs hatch.

Those products are:

• imidacloprid (most commonly available as Merit™, but now that the active
  ingredient has gone "off patent", there are several other trade names available.
  
• chlothianidin (Arena™) The company (Arysta) claims that the product is active
  against a wide range of turf insects, and some turf entomologists in other parts
  of the country recommend that it be applied slightly earlier in the season to
  provide control of some of those pests. Because our New England grub complex is
  a little trickier to manage than grubs in other parts of the country, we still
  suggest that the traditional timing (during egg laying or shortly thereafter) be
  followed.
  
• thiamethoxam (Meridian™) The company also claims that the product is active
  against a wide range of turf insects. The same comments for chlothianidin apply.

Billbugs
Dave Shetlar, turf entomologist at The Ohio State University, is cautioning turf managers in the Midwest to be on the alert for bluegrass billbug outbreaks this year. The relatively dry conditions this spring tend to work to the advantage of the billbugs. Conditions in much of New England have been relatively dry recently as well, so the potential is there for this to be a "good" (or bad, depending on your outlook!) year for billbugs.

Submitted by: Dr. Pat Vittum

DISCLAIMER - As always, it is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. The author and the University of Massachusetts are not liable for any consequences of any pesticide "recommendations". Mention of any trade name is not to be considered endorsement of a product.

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